﻿// Copyright 2004-2011 Castle Project - http://www.castleproject.org/
// 
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
// 
//     http://www.apache.org/licenses/LICENSE-2.0
// 
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#region 导入名称空间

using System;
using System.Diagnostics;
using System.Reflection.Emit;

#endregion

namespace LightWork.DynamicProxy.Generators.Emitters.SimpleAST
{
    /// <summary>
    /// Wraps a reference that is passed
    /// ByRef and provides indirect load/store support.
    /// </summary>
    [DebuggerDisplay("&{OwnerReference}")]
    public class IndirectReference : TypeReference
    {
        public IndirectReference(TypeReference byRefReference) :
            base(byRefReference, byRefReference.Type.GetElementType())
        {
            if (!byRefReference.Type.IsByRef)
                throw new ArgumentException("Expected an IsByRef reference", "byRefReference");
        }

        public override void LoadAddressOfReference(ILGenerator gen)
        {
            // Load of owner reference takes care of this.
        }

        // TODO: Better name

        public override void LoadReference(ILGenerator gen)
        {
            OpCodeUtil.EmitLoadIndirectOpCodeForType(gen, Type);
        }

        public override void StoreReference(ILGenerator gen)
        {
            OpCodeUtil.EmitStoreIndirectOpCodeForType(gen, Type);
        }

        public static TypeReference WrapIfByRef(TypeReference reference)
        {
            return reference.Type.IsByRef ? new IndirectReference(reference) : reference;
        }

        // TODO: Better name
        public static TypeReference[] WrapIfByRef(TypeReference[] references)
        {
            var result = new TypeReference[references.Length];

            for (var i = 0; i < references.Length; i++)
                result[i] = WrapIfByRef(references[i]);

            return result;
        }
    }
}